I had no idea when they were 'starting' - I was just numbed, they kept sweeping an ice cube over me and asking when I could feel it, then they got a curtain up, there was some intermittent pulling and tugging, and then they lifted up a baby!
Btw, you can mention to your MW if you have any strong preferences or things you'd rather avoid during your CS (you can of course do a birth plan if you want to). Some women seem to really want to know what's going on, others really don't want to know. You can let them know which you prefer.
I used breathing and relaxation techniques when the spinal was put in - which was fine, the only pain was from the anaesthetic injection they give you before they site the spinal needle. No more than you'd get at the dentist (less, in fact - I can't stand injections in my mouth).
If you want, you could do some basic prep in terms of breathing and relaxation/visualisation exercises - you don't have to have a VB for these things to be helpful! I use them in traffic jams...
But if you don't fancy it, remember that there is a surgical team there who are very used to dealing with anxious patients, and it is part of their job to keep you calm and happy. I had a wonderful anaesthetist, who was friendly and chatty (not too chatty), and reassuring - they sit right by your head, and have to monitor how you are, blood pressure etc, and so it is in their interests to have a good relationship with you in theatre, and to communicate well.
It really is over very fast. They get the baby out very quickly - most of the time is spent stitching you up afterwards, but by then you will have a baby to gaze at and touch, so that time goes by very fast. Or did for me, anyway. DS was held up for me to see - applauded by theatre staff as he yelled! - taken to the side of the room, within my sight for cord cutting and cleaning, and then plonked beside my head straightaway so I could touch him and say hello etc.
Btw. I read a brilliant description of a CS on this board very recently - I'll try and find it, you might find it useful.